The present invention relates to a tray storing and feeding apparatus which is used, for example, for handling a tray on which various components such as electronic components are aligned and stored in rows, and for feeding these stored components for the purpose of manufacturing an electronic circuit substrate.
A conventional apparatus of such type usually includes a tray carrier 53 which is driven vertically by a cylinder 59 for transferring a tray 51 in a tray storage section 52 as shown in FIGS. 5 and 6A-6D. The tray carrier 53 is also driven, at its lowered position, to transfer the tray 51 between a point just under the tray storage section and a position (not shown) where it receives a tray or a position (not shown) where it supplies the components accommodated on the tray 51. Provided at the tray storage section 52 is a pair of clamp members 55 which are opened and closed via a toggle 58 by a cylinder 59 shown in FIG. 5. This pair of clamp members 55 have on their opposing surfaces respective projections 64 which enter into a gap 62 between the trays 51 piled upon each other in the tray storage section 52 as shown in FIG. 6C and engage with the lower face of a tray immediately thereabove from both sides as shown in FIGS. 6A, 6C, and 6D. The projections 64 come to engagement with the tray 51 in such a way as shown in the order of FIGS. 6B and 6C, so that the tray under which the projections 64 are inserted is supported together with other trays piled thereabove in the tray storage section 52. Trays 51 under the projections 64 are received on the tray carrier 53 and descended as shown in FIG. 6D, thus being separated from the other trays 51 supported in the tray storage section 52. The separated tray 51 may be further moved to a position where the components are fed for use. Conversely, a tray 51 may be brought upward by the tray carrier 53 and be received in the tray storage section 52, after which the projections 64 are inserted under the lowermost tray for supporting the same in the order of actions respectively shown in FIGS. 6D, 6C, 6B, and 6A.
The tray 51 can be thereby automatically piled upon one another and stored in the tray storage section 52, or can be separated one by one from the stack of trays and fed to a prescribed position for supplying the components for use.
However, trays 51 which are available on the market are generally such that the space between the two trays piled upon one another is varied. Trays of some types do not allow the projections 64 of the clamp member 55 to enter into a space between two trays one upon another, in which case the trays 51 cannot be separated from each other. In particular, trays of small type form a very small or almost no space between them when piled upon one another, and in such a case it is impossible to separate the trays from each other.
The tray 51 may be held only by means of a frictional force from both sides without such projections as described above. In that case, a clamping force of the clamp member 55 must be strong enough to bear the weight of the tray 51, otherwise the tray 51 may fall, which would cause a serious problem in practice.
An object of the present invention is to provide a tray storing and feeding apparatus which is capable of certainly separating and feeding trays irrespective of spacing conditions between two trays piled upon one another while being safely constructed such as to prevent the tray from falling off.
Another object of the present invention is to provide an apparatus for handling an electronic component such as a bump bonder or electronic component mounting device in which such tray storing and feeding apparatus as mentioned above is incorporated.
To accomplish the above object, an improved tray storing and feeding apparatus of the present invention comprises a tray carrier which is movable vertically in a tray storage section for transferring a tray, a tray receiver provided in the tray storage section which is capable of opening and closing for engaging with and retracting from the tray being transferred by the tray carrier, a tray holder which opens and closes for holding the tray from both sides, and an open/close mechanism which causes the tray receiver and the tray holder to open and close timely.
With such a structure, the tray receiver and the tray holder are opened and closed timely by the open/close mechanisms such that when one tray is lifted up to the tray storage section by the tray carrier, the tray receiver is opened prior to the opening action of the tray holder. Thus, even when the space between the two trays is small or even if there is no space therebetween, the tray being lifted up can reach the tray storage section where the other trays are held by the tray holder. After that, the tray holder is opened so as to allow the tray which has been lifted up to be received at the tray storage section. When there is no other trays, the tray which has been lifted up is stored solely, and when there are other trays that are previously stored, the trays are all lifted up together so as to store the trays in a stack. Each time one tray is stored, the tray receiver and the tray holder are closed, so that the tray receiver can engage with the lower face of the newly stored tray from both sides, thereby supporting the tray. As the tray holder holds the newly stored tray from both sides at the same time, the tray can be stored safely without possibility of falling off by its own weight. Since the moment when the tray is held only with the tray holder during the tray needs to be supported is only an instance when the tray carrier is slightly lowered after the tray has been lifted up to the tray storage section, the tray will thus hardly drop, and the above-said safety is ensured.
When separating the trays one by one from the tray stack and transferring the tray to a prescribed position for feeding the components, after the tray receiver and the tray holder are opened and the tray is placed on the tray carrier which has been moved upward, the tray holder is closed prior to the closing action of the tray receiver only when the tray carrier has been descended by an amount which is equivalent to a height of one tray in the tray stack. The lowermost tray is thus separated from the other trays by further lowering the tray carrier 3, and the tray receiver is closed at the point when the lowermost tray is lifted down to a certain height, where the tray receiver can return to the state in engagement with the lower face of the tray from both sides without any interference between itself and the lowermost tray which has just been separated. Accordingly, even when the space between the trays piled upon one another is small or even if there is no such space, the trays stored in a stack can be reliably separated one by one from each other. Since the moment when the tray is held only with the tray holder while the tray needs to be supported is only for an instance when the lowermost tray is being lowered to the outside of the tray storage section so that it does not obstruct the closing action of the tray receiver during the time when one tray is separated from the others, the tray will hardly fall and the above said safety is ensured.
In addition, the present invention is characterized in that the tray receiver is urged to remain in engagement with the tray, and that the open/close mechanism for the tray receiver is constructed such that a cam provided to the tray carrier causes the tray receiver to retract sidewards via a cam follower provided to the tray receiver in synchronism with the upward movement of the tray carrier, and with the downward movement of the tray carrier, the cam causes the tray receiver via the cam follower to return to the position in engagement with the tray.
With such a structure, the tray receiving member is always urged to be engaged with the lower face of the tray, and opening and closing actions of the tray receiving member are precisely repeated with mechanical timing, which can be preliminarily determined, by means of the cam and the cam follower. The tray receiver can be thus timely opened and closed without failure with simple and inexpensive structure.
Further, in order to accomplish the above said objects, a bump bonder according to the present invention comprises a first tray storing and feeding apparatus including a first tray storing unit where trays accommodating IC chips before formation of a bump are stored in an accumulated state, a second tray storing unit for storing empty trays in a stack, and a first tray carrier for taking out a lowermost tray in the first tray storing unit and transferring the same to a chip loading position, and for transferring a tray which has been emptied at the chip loading position to the second tray storing unit and storing the same from below in the second tray storing unit; a second tray storing and feeding apparatus including a third tray storing unit where trays accommodating IC chips on which a bump has been formed are stored, a fourth tray storing unit for storing empty trays in a stack, and a second tray carrier for taking out a lowermost tray in the fourth tray storing unit and transferring the same to a chip unloading position, and for transferring a tray at the chip unloading position which has been filled with IC chips with a bump formed thereon to the third tray storing unit and storing the same from below in the third tray storing unit; a transfer head which picks up an IC chip before formation of bumps from the tray located at the chip loading position, transfers the same onto a bonding stage, picks up an IC chip on which a bump has been formed on the bonding stage, and transfers the same onto a tray located at the chip unloading position; and a bump forming unit for forming a bump on an IC chip positioned on the bonding stage, the first and second tray storing and feeding apparatuses being the tray storing and feeding apparatus as described above.
By adopting the tray storing and feeding apparatus of the present invention to the bump bonder as set forth above, tray exchange can be accomplished without stopping operation of the bump bonder. Moreover, trays can be readily loaded to and unloaded from each of the tray storing units.
Tray storing and feeding apparatus of the present invention may also be incorporated in any other apparatuses which handle electronic components such as an electronic component mounting device, which will be similarly advantageous as in the case of bump bonder described above.